农林科学最新文献

Copy number variations (CNVs) have become widely acknowledged as a significant source of genomic variability and phenotypic variance. To understand the genetic variants in horses, CNVs from six Indian horse breeds, namely, Manipuri, Zanskari, Bhutia, Spiti, Kathiawari and Marwari were discovered using Axiom^™ Equine Genotyping Array. These breeds differed in agro-climatic adaptation with distinct phenotypic characters. A total of 2668 autosomal CNVs and 381 CNV regions (CNVRs) were identified with PennCNV tool. DeepCNV was employed to re-validate to get 883 autosomal CNVs, of which 9.06% were singleton type. A total of 180 CNVRs were identified after DeepCNV filtering with the estimated length of 3.12 Kb-4.90 Mb. The functional analysis showed the majority of the CNVRs genes enriched for sensory perception and olfactory receptor activity. An Equine CNVs database, EqCNVdb (http://backlin.cabgrid.res.in/eqcnvdb/) was developed which catalogues detailed information on the horse CNVs, CNVRs and gene content within CNVRs. Also, three random CNVRs were validated with real-time polymerase chain reaction. These findings will aid in the understanding the horse genome and serve as a preliminary foundation for future CNV association research with commercially significant equine traits. The identification of CNVs and CNVRs would lead to better insights into genetic basis of important traits.

This review examines the role of the canine blood-brain barrier (BBB) in health and disease, focusing on the impact of the multidrug resistance (MDR) transporter P-glycoprotein (P-gp) encoded by the ABCB1/MDR1 gene. The BBB is critical in maintaining central nervous system homeostasis and brain protection against xenobiotics and environmental drugs that may be circulating in the blood stream. We revise key anatomical, histological and functional aspects of the canine BBB and examine the role of the ABCB1/MDR1 gene mutation in specific dog breeds that exhibit reduced P-gp activity and disrupted drug brain pharmacokinetics. The review also covers factors that may disrupt the canine BBB, including the actions of aging, canine cognitive dysfunction, epilepsy, inflammation, infection, traumatic brain injury, among others. We highlight the critical importance of this barrier in maintaining central nervous system homeostasis and protecting against xenobiotics and conclude that a number of neurological-related diseases may increase vulnerability of the BBB in the canine species and discuss its profound impacts on canine health.

Chronic Kidney Disease (CKD) is one of the most common conditions affecting felines, yet the metabolic alterations underlying its pathophysiology remain poorly understood, hindering progress in identifying biomarkers and therapeutic targets. This study aimed to provide a comprehensive view of metabolic changes in feline CKD across conserved biochemical pathways and evaluate their progression throughout the disease continuum. Using a multi-biomatrix high-throughput metabolomics approach, serum and urine samples from CKD-affected cats (n = 94) and healthy controls (n = 84) were analyzed with ultra-high-performance liquid chromatography-high-resolution mass spectrometry. Significant disruptions were detected in tryptophan (indole, kynurenine, serotonin), tyrosine, and carnitine metabolism, as well as in the urea cycle. Circulating gut-derived uremic toxins, including indoxyl-sulfate, p-cresyl-sulfate, and trimethylamine-N-oxide, were markedly increased, primarily due to impaired renal excretion. However, alternative mechanisms, such as enhanced bacterial formation from dietary precursors like tryptophan, tyrosine, carnitine, and betaine, could not be ruled out. Overall, the findings suggest that metabolic disturbances in feline CKD are largely driven by the accumulation of gut-derived uremic toxins derived from precursors highly abundant in the feline diet. These insights may link the strict carnivorous nature of felines to CKD pathophysiology and highlight potential avenues for studying preventive or therapeutic interventions.

Copy number variations (CNV) are important genetic variations. The endogenous factors cobalamin receptor (CUBN) and MIA SH3 domain ER-derived factor 3 (MIA3) are associated with bone/muscle development and intramuscular fat deposition. There have been no reports on the effects of CUBN and MIA3 CNVs on growth traits of Chinese cattle. This study aimed to determine the correlation between the CUBN and MIA3 CNVs and growth traits in Chinese cattle. qRT-PCR was used to detect the distribution of CUBN and MIA3 CNV and the expression levels of their mRNA, and correlation analysis was conducted between CNV and growth traits. The CUBN was differentially expressed in different breeds of cattle, and CUBN CNV correlated significantly with body height, hip height, body slanting length, and hip width of Grassland Red cattle (CYH); eye muscle area of Yanbian cattle (YB) and Yan Yellow cattle (YH). MIA3 showed no CNV in CYH and YB cattle, and only one deletion type occurred in YH cattle. CUBN and MIA3 mRNA have different expression patterns in different cattle breeds and tissues. In conclusion, CUBN CNV is correlated significantly with growth traits in Chinese cattle and is a novel molecular marker that could be exploited in cattle breeding.

Ex situ conservation is an important wildlife conservation strategy, but endangered wildlife in captivity often exhibit high disease rates. Commensal microorganisms are vital for homeostasis, immunity, and linked to diseases. This study analyzed the structure, assembly, variations of the symbiotic microbiota of the endangered crocodile lizard, and their relationship with environment, as well as the effects of captivity on them, to explore why captive reptiles face high dermatosis rates. Results showed that the reptile's microbiota significantly differ from that of its habitat, demonstrating niche specificity. While species richness among organs showed no significant differences, microbial diversity varied considerably. Skin microbiota showed no site-specific clustering. The assembly of skin, oral, and intestinal bacterial communities was dominated by homogeneous selection. The gut and oral bacterial networks were resilient to disturbances, while the skin bacterial network was sensitive. Captivity primarily affected the skin microbiota, reducing its diversity and stability, thereby increasing disease risk, and these effects were not solely attributable to environmental changes. These findings suggested that skin microbial changes in captive reptiles may be responsible for their increased susceptibility to dermatosis in ex situ conservation. This study underscored the importance of understanding reptile-associated microbes for effective conservation strategies and offers potential solutions.

Senecavirus A (SVA) is the causative agent associated with porcine idiopathic vesicular disease (PIVD), a condition indistinguishable from other foreign vesicular diseases affecting pigs. This complicates differential diagnosis and impacts the global swine industry. A diagnostic ELISA based on a non-structural viral protein has been developed, capable of distinguishing infected from vaccinated animals (DIVA). Different expression systems (eukaryotic and prokaryotic) were used to express recombinant proteins. The baculovirus-expressed SVA 3AB DIVA ELISA demonstrated a sensitivity of 96.67% and specificity of 96.67%. In contrast, the E. coli-expressed SVA 3AB DIVA ELISA achieved 100% sensitivity and 93.33% specificity. Both ELISAs strongly correlated with the reference method and showed no cross-reactivity with other pig pathogens. The E. coli system also provided a higher yield of expressed protein than the baculovirus system. These findings indicate that SVA DIVA ELISAs are effective alternatives for detecting SVA antibodies. They can be valuable tools for sero-surveillance and for evaluating immunity status tests to support and approve vaccination programs for pig herds in the future.

Salmonella Pullorum, the causative agent of pullorum disease, posing a significant threat to the global production of poultry meat and eggs. However, existing detection methods have substantial limitations in efficiency and accuracy. Herein, we developed a genomic deletion-targeted TaqMan qPCR assay for identification of Salmonella Pullorum, enabling precise differentiation from other Salmonella serovars. The assay's detection limit was 5 copies/μL of plasmid and 4 CFU/μL of bacterial DNA. Furthermore, we collected 676 chicken samples from an established infection model to compare the performance of the TaqMan qPCR assay with traditional bacterial culturing and antibody-based detection approaches. With superior sensitivity and specificity, the newly developed method detected over 80% of positive chickens, significantly outperforming the two conventional methods. Moreover, we proposed a combined framework that incorporates the advantages of TaqMan qPCR assay and antibody detection method, further enhancing the detection rate of positives to 92%. Additionally, to address the frequent aerosol contamination of amplification products in laboratory settings, we devised an easy-to-deploy anti-contamination system based on T7 exonuclease. Overall, the T7 exonuclease-assisted TaqMan qPCR assay will not only upgrade the current detection for pullorum disease, but also exemplify the feasibility of targeting specific genomic deletions for pathogen detection.

Variation in litter size (LS) in sheep is linked to genetic factors, including the Zona pellucida-3 (ZP3) gene, which plays a role in ovine reproductive processes. This study examined the association between ZP3 gene variations and LS in Kari sheep. Two groups of 160 Kari ewes were analysed: one consistently producing singletons and another producing twins, with occasional triplets. Additionally, Madakhlasht sheep, which sometimes produce twins, and Balkhi sheep, which produce only singletons, were used as references. The entire ZP3 gene was amplified using PCR and sequenced at 30× with Next Generation Sequencing. Bioinformatics analysis identified 70 variants across the three breeds, located in upstream regions, introns, and exons. Notably, two point mutations and a six-nucleotide insertion were found upstream of the initiation codon in twin-producing Kari ewes, potentially affecting ZP3 expression and LS. Two missense mutations (I101L in exon 1 and R408H in exon 8) were heterozygous in twin-producing Kari ewes but homozygous in other groups, correlating with LS. Protein modelling suggested that the I101L mutation alters the binding site, potentially impacting protein function. These findings indicate that ZP3 gene variations influence reproductive efficiency and LS in sheep, with specific variants serving as potential markers for selective breeding to enhance LS.

This study aims to establish an immortalized fibroblast cell line from Mongolian sheep. Primary Mongolian sheep fibroblasts (SSF) were isolated using tissue explant and enzymatic digestion methods, followed by microscopic observation, growth curve plotting, and karyotype analysis. The results confirmed the successful isolation of SSF. Human (hTERT) and sheep (sTERT) telomerase reverse transcriptase vectors were separately introduced into SSF, with cells passaged up to 36 generations following G418 selection. Microscopic examination and qRT-PCR results demonstrated that TERT transfection did not alter the morphology of SSF and led to stable, high levels of TERT expression (P < 0.01). Cell counting and flow cytometry revealed that TERT-transfected cells had higher viability and lower apoptosis rates compared to SSF (P < 0.05). Karyotype and soft agar colony formation assays indicated that hTERT and sTERT-transfected cells maintained normal characteristics without malignant transformation. β-galactosidase staining indicated that TERT transfection significantly reduced cellular senescence (P < 0.001). Additionally, sTERT-transfected cells exhibited higher TERT expression, enhanced viability, proliferation, and anti-senescence effects compared to hTERT-transfected cells (P < 0.05). In summary, the introduction of hTERT and sTERT effectively extends the lifespan of SSF, with sTERT demonstrating a more pronounced effect. This study provides critical evidence for preserving Mongolian sheep genetic resources and developing immortalized cell lines.

Insulin-like Growth Factor 2 mRNA-binding Protein 1 (IGF2BP1) is a candidate gene of significant interest for modulating economically important traits in livestock and poultry. The second intron of IGF2BP1 has been implicated in growth-related traits, though its precise mechanistic role remains elusive. Initial resequencing analyses in our laboratory indicated strong selective pressures on the IGF2BP1 genomic region, prompting the selection and identification of several single nucleotide polymorphisms (SNPs). Seven SNPs were mapped to the conserved region of the second intron, necessitating further investigation into their functional relevance and association with growth traits. In this study, 348 Nanjiang Yellow goats were analyzed, and the association analysis via the GLM program in SAS 9.4 identified five SNPs significantly correlated with growth traits. Notably, rs652062749(A > G) emerged as a critical locus influencing later-stage growth traits. Furthermore, strong linkage disequilibrium was observed among three SNPs, with the rs638185407 (T > A) variant markedly enhancing luciferase activity in H293T cells. Combination genotypes TTAACT, TTCCCC, and ATCACT were identified as superior for growth traits, offering theoretical insights for genetic co-breeding. This study underscores the potential utility of IGF2BP1 as a functional genetic marker in Nanjiang Yellow goat breeding programs.